/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.tickaroo.tikxml.converter.htmlescape;

import java.io.IOException;
import java.io.Writer;

/**
 * Executes a sequence of translators one after the other. Execution ends whenever the first
 * translator consumes codepoints from the input.
 *
 * @since 3.0
 */
public class AggregateTranslator extends CharSequenceTranslator {

  private final CharSequenceTranslator[] translators;

  /**
   * Specify the translators to be used at creation time.
   *
   * @param translators CharSequenceTranslator array to aggregate
   */
  public AggregateTranslator(final CharSequenceTranslator... translators) {
    if (translators == null) {
      this.translators = null;
    } else {
      this.translators = translators.clone();
    }
  }

  /**
   * The first translator to consume codepoints from the input is the 'winner'. Execution stops with
   * the number of consumed codepoints being returned. {@inheritDoc}
   */
  @Override
  public int translate(final CharSequence input, final int index, final Writer out)
      throws IOException {
    for (final CharSequenceTranslator translator : translators) {
      final int consumed = translator.translate(input, index, out);
      if (consumed != 0) {
        return consumed;
      }
    }
    return 0;
  }
}